cammellostanco

Hi all! So I decided to give to my 9398 crawler a new life, connecting to the v2 PF IR receiver a 3S lipo. I have used this approach. The battery I used is this, I soldered a balance plug to a PF extension cable so I could keep the IR receiver untouched. Now, the power is amazing, but I have now way of deciding it's speed. The motors are either ON or OFF. Is there a way, with my current setup, to regulate the speed? Let me give you an example: On my other crawler, the 42099 (Lego Powered UP) , when I use the Lego Control+ app, I can decide the speed of the truck depending on how much I push the trigger on the app, but it seems I cannot achieve the same on the old PF motors. Ideas are welcome!

Hey thank you everyone for the input, I did not set the topic to "follow", so I missed your msgs the first time. I will read through and let you know!! Would this give me the ability of decide the amount of power output?

Hi, I was using lithium before, the NiZn are stronger. Also, my Energizer lithium report 1.5v, while NiZn 1.6v

Hi everybody! It seems that I just cannot get enough power out of the 2 std motors anymore. I tried with both alkaline batt as well as TOP enelopp rechargable, but no way, the crawler is not capable of pulling itself on the same slopes it used to when I tested it in the winter :( What can I try? Any ideas?

While I wait for the new IR receiver, I went ahead and connected the old IR v2 receiver to a 3S LiPo: the thing is a monster I know I did not find the solution, but with the abundance of power, the truck is now as fast as the 42099 crawler on NiZn AA and increased reduction gearing. I have put back in the 9398 the modified gears in the hubs, that is I have used again the increased reduction gears of my previous post. Let's see what happens with a new controller

Just installed NiZn batteries on 42099, WOW, what a difference compared to NiMh. Let's see if the hold many recharge cycles and also let's hope I do not overstress the motors.

I have a V2, I purchased a new one on Aliexpress, we'll see.

Thank you for helping out. I have plugged both motors directly into the hub (brand new Energizer Lithium). Front Motor: very strong, no problem. If I hold the wheels very tight, there is no whining noise from the motor. Rear: seem to be ok as well, If I hold the wheels very tight, there is no whining noise from the motor. When I connect both motors, and I hold the FRONT wheels all 4 stop, with no whining. All 4 wheels start to spin again as soon as I let go. If I hold the REAR wheels, all 4 stop and do not re-start when I let go. Very weird: after taking apart the wheels hubs and the front/rear axles and lubricating them, the 9398, though still weak, improved a lot.... Who knows??!!! I do not think point 3 is indicative of anything though. I am waiting for a new battery pack and a 3S LiPo to see if the results are different. When I will have the $ I will try with Buwizz. On the same track the 42099 running on 1.2v NiCd greatly outperforms the 9398 on new Energizer Lithium , I point the issue to the battery pack. Will post updates as soon as I can do more testing.

OK, I replaced the gears as per the original manual. I am using brand new energizer lithium. I had to disconnect the front motor since I lost the original hub gears. It helped towards a solution, but it's not there yet The only change is that the truck now goes back and forth faster 4 or 5 times, before stopping as before.

This is a video of the noise that engines make. If I lift the truck the wheels spin again, as soon as I put it down, the whining starts again and the motors does not spin. The truck has the original open diffs, the only thing I changes is the reduction gears in the hubs. Here the pictures where I swapped the gears to get more torque, did I overdo it?

Thanks, I checked, the rims are fine, they are not slipping on the tire. I am going to make a video so the issue is clearer.

After just a few years....I revived my passion for Lego Technic. And yes... the problem with the poor output is still there. Let me recap: I removed both motors, checked the axles, etc. There is no excess friction and the motor look fin externally Both motors still have their original specs speed (400/420 rpm) measured with the yellow Lego speedometer tool I could not recover anymore the instructions to connect a 9V battery to the motor directly, any ideas?

Hello again guys, I did some testing, it appears that the issue is still there, I will be now going to test the other options you mentioned. Will update asap

hi guys, back again. I admit I was lazy and did not work at the lego for quite some time. Decided to revive it and troubleshoot the problem. I got a new battery charger and a battery tester, the 6 batteries work fine, BUT the 4x4 is still slugghish with almost no torque. More testing tomorrow

Ok, i still have the warranty. But before changing the 2 motors (looong wait) what can I try? I will try the motors connected directly to the battery box anyway. The 2 motors are hardy used (10 times or less)

First post... I just got the awesome 9398... I was at a car dealer, when I stumbled on a Lego Box ... my girlfriend was also charmed and in 15 mins we were both buying again our Lego!! After 20 years ! So ... to the 9398, excellent machine, huge fun to build and watch watch it move its first metres...! I spent some time yesterday playing in the snow... stock tyres are really NOT OK for off roading! I got myself four <Hpi Racing Ground Assault>, soooo much better. Only drawback: they're too wide and , unless you glue them, they stay off the rim on the external side...

Yes, indeed, the HPI tyres are awesome on any terrain, sooo much softer. I'd love to have bigger rims though! Videos were SHOT in HD.... I did mess up big time during post production.... sorry

And, as promised, I have changed to 8:24 the gearing on each wheel plus installed a different (hugher) protection plate on the gears at the front/bottom of the truck. Here some test with different setups. This thing is a monster

WoW I did discover a whole new world! Thank you all... I am keen on reading, unfortunately, getting the pieces is expensive ... :(

From this very first and rough pic, you can see the tyres. They are really coming out of the rim.... but I did not want to glue them onto the rims... http://www.brickshelf.com/gallery/cammellostanco/9398-Mods/img_20121209_005022.jpg